Composite board.



- No. 759,899. PATENTED MAY 17, 1904.

' W. A. LYNCH.

COMPOSITE BOARD;

. APPLIOATION FILED AUG- 8, 1902.

F N0 MODEL. 1

UNITED STATES fatented May 17, 1904.

WILLIAM A. LYNCH, OF CANTON, OHIO.

COMPOSITE BOARD.

SPECIFICATION forming part of Letters Patent No. 759,899, dated May 17, 1904.

7 Application filed August 8, 1902. Serial No. 118,918Va (No model.)

To all whmn it may concern.-

Be itknown that I, VVILLIAM A. LYNCH, a citizen of the United States, residing at Canton, in the county of Stark and State of Ohio, have invented certain new and useful Improvements in Composite Boards, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an improvement in composite boards, the object beingto produce board-like articles which can be built up of relatively weak pieces of wood of little cost and which when completed shall be greatly increased in strength and able to withstand high transverse strains which would tend to break the boards either when applied on lines transverse to the fibers or on lines parallel with them. Boards of this kind are espe' cially adapted for use in the construction of heavy floorings, as the bottoms of automobiles, the floors of cars. the walls of freightcars, &c.

In the drawings, Figure 1 shows in plan a section of a composite board embodying my improvements. Fig. 2 is a cross-section on the line 00 w of Fig. 1. Fig. 3 is an end view of the strips or pieces of wood of the upper set. Fig. 4: is a similar View of the pieces or strips of the lower set. Fig. 5 shows the corrugated steel. Fig. 6 is a plan view of a piece of the latter.

I have selected for illustration a board-like structure and the component parts shown in the drawings.

A A are a series of counterpart wooden strips, and B B indicate others of like character.

A and B indicate strips or pieces of wood similar in essential character to those at A and B, but difi'ering therefrom in width. In practice a relatively thin wooden board or strip, such as shown by the dotted lines at a and the full lines a, is subjected to the action of a planing or equivalent machine and a series of grooves a formed therein, the tongues or ribs (0 being left. The component strips or pieces can be made in large quantities ready for building up composite boards of any desired width.

D indicates aplate of sheet metal uniformly and evenly corrugated, as shown in Fig. 5, this shaping of the steel being accomplished by crimpingrollers or other suitable machines. When it is desired to. build up the composite article, a section of the steel is taken and into the grooves or corrugations on the under side are fitted a series of the grooved wooden strips B B, suflicient in number to give the desired width. Then a series of bars or strips A A are similarly placed in the cor- 6O rugations or depressions in the upper side. By preference I so arrange the lower row of wooden strips and the upper row that I break joints, as shown in Figs. 2 and 3. After the parts have been fitted together they are 6 5 subjected to pressure sufficient to effect a tight and firm union. This union may be maintained by the use of a suitable adhesive material, although originally I prefer to effect a permanent rigidity of fastening by means 7 of screws or nails, as shown at E, some passing through the lower layer of wood, then through the sheet-steel and into the wood of the upper layer, and others being passed downward from the upper wood through the steel to the lower. From an examination of the drawings it will be seen that I in this way produce from the initial relatively thin and relatively weak strips of wood a board-like device of considerably greater thickness and reinforced in such way that it is increased in strength to a great extent. If a stress should be exerted downward in such way as to carry or tend to carry the fibers at lines between the side edges downward and parallel to said side edges, 5 this is resisted by the overlapping of the tongues Z) Z) of the lower pieces of wood upon the tongues or projections a in the upper pieces that is to say, the tendency of those on the upper pieces to spread is resisted by the 9 wedging or crowding action of those on the lower pieces, and the intervening plate of erimped or corrugated steel not only distributes this balancing of the tendencies to bend, but itself serves as a resistant.

What I claim is 1. A composite board or bar having an upper piece or pieces of wood formed with ribs or projections a and intervening grooves or depressions, a lower piece or pieces of wood I00 of Wood, each piece having one or more similar ribs and recesses, and the interposed corrugated sheet-metal strip extending continuously across both the upper and the lower series of pieces, and having its corrugations pressed into the grooves or corrugations in the wood, the wood pieces of the upper series being arranged to break joints in relation to the pieces of the lower series, substantially as set forth.

3. The composite board or bar having an upper series of pieces of wood each formed with one or more ribs or tongues a, and recesses or grooves at the sides of each rib, a lower series of pieces of wood each having one or more similar ribs and recesses, one or both of said series having one or more relatively Wider and one or more relatively narrower strips, and the interposed corrugated sheet-metal strip pressed into the grooves or recesses in the wooden strip, the said relatively narrow strips being arranged substantially asset forth to have the lines of contact of the strips of one series break joints with the strip of the other series.

In testimony whereof I aflix my signature in presence of two witnesses.

WVILLIAM A. LYNCH.

Witnesses:

SIMEON G. DOMER, ,GRAoE A. McCLURE. 

